Dispensing Device with a Spray Assembly

ABSTRACT

The spray assembly of a dispensing device is arranged together with a mixing assembly inside a mixing and spray head, the mixing assembly being arranged before the swirl chamber of the spray assembly, and the mixing and spray head, which forms a unit, being removably attached to a multicomponent dispensing appliance. The result is a more homogeneous spray action, on one hand, and an easy replacement of the head, on the other hand.

The present invention relates to a dispensing device with a spray assembly according to the preamble of claim 1. A device of this kind is e.g. known from U.S. Pat. No. 4,260,110, which patent mainly relates to the design of a spray nozzle, however. This patent specification only discloses dispensing devices having a spray nozzle for a single component.

For certain medical applications, however, two-component materials are stored in double syringes or double cartridges, mixed by means of static mixers and dispensed using different application instruments. For large surface dispensing or when a distribution of the mixed materials by means of an applicator is not possible, a spraying system has to be used. In conventional spray assemblies, the two-component materials are only mixed to a limited extent or compressed air is additionally required which in certain operations leads to undesirable aerosol formation and does not always ensure a homogeneous distribution of the two components on the sprayed surface.

On this background, it is the object of the present invention to provide a dispensing device by means of which two or more components are homogenously mixed prior to their entry into the spray nozzle. In addition, as the components harden after having been mixed and sprayed, the mixing and spray assembly should be exchangeable in the simplest possible manner. This is accomplished by the dispensing device according to claim 1.

The invention will be explained in more detail hereinafter with reference to drawings of exemplary embodiments.

FIG. 1 shows a first exemplary embodiment of a dispensing device according to the invention in a perspective view,

FIG. 2 shows an enlarged detail of FIG. 1,

FIG. 3 shows the mixing and spray head of FIG. 2 in the assembled condition,

FIG. 4 shows a section according to line IV-IV in FIG. 3,

FIG. 4A shows a partial view of an embodiment variant of the mixing and spray piece of FIG. 4 with a compressed air inlet,

FIG. 5 shows a section according to line V-V in FIG. 4,,

FIG. 6 shows a section according to line VI-VI in FIG. 4,

FIG. 7 shows a section according to line VII-VII in FIG. 6,

FIG. 8 shows a second exemplary embodiment of a dispensing device according to the invention in a perspective view,

FIG. 9 shows a section through the assembled mixing and spray head of FIG. 8, and

FIG. 10 shows a section according to line X-X in FIG. 9.

Dispensing device 1 according to FIG. 1 includes a double syringe 2 and a mixing and spray head 3 that is attachable thereto. In a known manner, the double syringe comprises two storage containers 4 and 5 having equal volumes or equal cross-sectional areas, respectively, or cross-sectional areas whose ratio is different from 1:1. The two components are dispensed by means of a double plunger 6.

Mixing and spray head 3, hereinafter called “head” for the sake of simplicity, is essentially composed of three parts, namely a transfer housing 7 and a mixing and spray piece 8 that may be connected to the transfer housing by snap means, welding, cementing, a screw connection or by means of a bayonet coupling.

Basically, the head may be coupled to the dispensing appliance in different ways, for example by bayonet coupling means or by a screw connection. Advantageously, however, the head is simply plugged onto the dispensing appliance and easily removable therefrom by a connection as it is described in Swiss patent application no. 00453/06 to the applicant of the present invention. To this end, fastening area 9 on the outlet side of the dispensing appliance has an outlet flange 10 on which the two individual outlets 11 and 12 are arranged. Each outlet 11 and 12 has an essentially diametrically arranged, outwardly directed ridge 13 respectively 14 that tapers from outlet flange 10 toward the outlet. Each ridge has a saddle portion 15 respectively 16 that ends at a distance from the outlet flange and is followed there by a snap nose 17 respectively 18, the snap noses engaging in recesses 19 and 20 in transfer housing 7, see FIG. 4.

The two saddle portions 15 and 16 have the same configuration, but saddle portion 15 has an end portion 21 on the outlet side while saddle portion 16 has none. The presence or absence of end portion 21 constitutes a coding means ensuring that the head can only be attached in an unequivocal orientation. Furthermore, on both sides of their connecting plane, the two outlets are provided with clamping guides 22. Additionally, outlet flange 10 has a visual coding nose 23 that serves as an orientation aid for the head, the latter having a corresponding orientation nose 24.

In FIG. 2, a head 3 consisting of two component parts is illustrated where mixing and spray piece 8 is fastened to transfer housing 7 while the end of the latter forms rear chamber bottom wall 44 of the mixing and swirl chambers. At its outlet side end, transfer housing 7 has a distributor socket 25 in which four distributor outlets 26 and two positioning grooves 27 are arranged. In the area of corrugation 28, the housing is compressible in order to disengage snap noses 17 and 18 from recesses 19 and 20, thereby allowing to withdraw the head.

As follows from FIG. 4, two longitudinal bores 29 and 30 are arranged in the distributor socket which communicate with transversal bores 31 and 32, these transversal bores leading to distributor outlets 26. The coding and orientation noses allow plugging the head onto the dispensing appliance in such a manner that longitudinal bores 29 and 30 are in line with outlets 11 and 12 of the dispensing appliance.

As appears in FIG. 2, longitudinal feed passages 33 extend from ends 26 of the transversal bores. In FIG. 4 it is shown that coupling portion 34 of mixing and spray piece 8 has a circumferential groove 35 for receiving a corresponding collar 35A on the transfer housing. Housing portion 34 further comprises two positioning cams 36 which engage in corresponding positioning grooves 27. Closure 37 of mixing and spray piece 8 has four longitudinal channels 38 opening into an annular mixing chamber 39 from where four feed passages 40 lead to a concentric swirl chamber 41 from which spray outlet 42 leads to the exterior.

In FIG. 4A, an embodiment variant is illustrated in which a compressed air inlet 60 is arranged on end plate 50 of mixing and spray piece 61 in order to achieve a better spray action in certain cases. The other parts of the head are the same.

In FIG. 6 it is visible that feed passages 40 and feed ducts 43 do not form the same angle with respect to the mixing chamber and are offset from one another. Moreover, the feed passages and the feed ducts and the swirl and mixing chambers, respectively, do not have to be arranged in the same plane with respect to the longitudinal axis of the head.

In FIG. 7 it is apparent that bottom wall 44 of the mixing chamber is plane while at the top, i.e. in closure 37, serrated mixing elements 45 are arranged which produce turbulences in order to mix the two components before they reach the swirl chamber from where they are sprayed through the spray outlet.

As mentioned in the introduction, the present invention essentially aims to provide a mixing assembly before the spray assembly, more particularly before the swirl chamber, in order to achieve an efficient mixture of the components prior to the actual spraying procedure. Instead of providing an annular, concentric mixing chamber having serrated mixing elements, it is also possible according to FIGS. 8 to 10 to provide a mixing assembly comprising a static mixing element as it is known per se.

Dispensing device 46 according to FIG. 8 includes the same dispensing appliance 2 and the same fastening area as in the previous example. The fastening area of transfer housing 47 is the same as in the previous exemplary embodiment whereas mixer socket 48 is configured for receiving a mixing assembly 49 in its interior and fastening means 50, 51 on its exterior in order to attach mixing and spray piece 58 to transfer housing 47, thereby forming mixing and spray head 55.

Mixing assembly 49 with mixing element 52 is fastened in the interior of closure 53 of mixing and spray piece 58 and forms a unit with the latter. Fastening means 50, 51 for the attachment of the mixing and spray piece to transfer housing 47 may be snap, bayonet, or screw connections, or it may be fastened by ultrasonic welding or cementing.

As follows from FIG. 10, closure 53 of the head has feed passages 54 arranged therein, e.g. three of them, which lead to a swirl chamber 56 in the same manner as in the previous example from where spray outlet 57 leads to the exterior.

Based on the two exemplary embodiments of a mixing chamber or of a mixing assembly, respectively, other possibilities of mixing assemblies can be designed by one skilled in the art by which the components, whose number may also be greater than two, are efficiently mixed shortly before the swirl chamber prior to being sprayed through the swirl chamber and the spray outlet. 

1. Dispensing device with a spray assembly, in which the spray assembly is arranged together with a mixing assembly for at least two liquid components inside a mixing and spray head, the spray assembly comprising: a swirl chambers in which the mixing assembly is situated before the swirl chamber, and wherein the mixing and spray head, which forms a unit, are removably attached to a multicomponent dispensing appliance.
 2. Device according to claim 1, wherein the mixing and spray head is formed of a mixing and spray piece that is connected to a transfer housing.
 3. Dispensing device according to claim 1, wherein the mixing assembly comprises an annular mixing chamber having serrated mixing elements.
 4. Dispensing device according to claim 3, wherein the mixing chamber has feed ducts for the components that are to be mixed and feed passages leading from there to the swirl chamber, the mixing chamber having mixing elements on its side opposite the bottom wall of the mixing chamber, in the closure of the mixing and spray piece.
 5. Dispensing device according to claim 1, wherein the swirl chamber is arranged concentrically to the mixing chamber and opens into a spray outlet.
 6. Dispensing device according to claim 1, wherein the mixing assembly is arranged in a mixer socket of the transfer housing and comprises a helical mixing element that is followed on its outlet side by the swirl chamber with the spray outlet.
 7. Dispensing device according to claim 6, wherein the end of the mixing assembly on the outlet side thereof forms the bottom wall of the swirl chamber opposite the spray outlet of the latter.
 8. Dispensing device according to claim 2, wherein the fastening areas of the dispensing appliance and of the transfer housing are configured for an attachment or removal of the mixing and spray head without a relative rotational movement.
 9. Dispensing device according to claim 8, wherein the fastening area of the transfer housing is deformable.
 10. Dispensing device according to claim 8, wherein the fastening area of the dispensing appliance has snap noses that are engaged in recesses formed in the transfer housing.
 11. Dispensing device according to claim 1, characterized in that wherein the closure of the mixing and spray piece is provided with a compressed air inlet.
 12. Dispensing device according to claim 2, wherein the mixing assembly comprises an annular mixing chamber having serrated mixing elements.
 13. Dispensing device according to claim 2, wherein the swirl chamber is arranged concentrically to the mixing chamber and opens into a spray outlet.
 14. Dispensing device according to claim 3 wherein the swirl chamber is arranged concentrically to the mixing chamber and opens into a spray outlet.
 15. Dispensing device according to claim 4, wherein the swirl chamber is arranged concentrically to the mixing chamber and opens into a spray outlet.
 16. Dispensing device according to claim 2, wherein the mixing assembly is arranged in a mixer socket of the transfer housing and comprises a helical mixing element that is followed on its outlet side by the swirl chamber with the spray outlet.
 17. Dispensing device according to claim 3, wherein the fastening areas of the dispensing appliance and of the transfer housing are configured for an attachment or removal of the mixing and spray head without a relative rotational movement.
 18. Dispensing device according to claim 4, wherein the fastening areas of the dispensing appliance and of the transfer housing are configured for an attachment or removal of the mixing and spray head without a relative rotational movement.
 19. Dispensing device according to claim 4, wherein the fastening areas of the dispensing appliance and of the transfer housing are configured for an attachment or removal of the mixing and spray head without a relative rotational movement.
 20. Dispensing device according to claim 5, wherein the fastening areas of the dispensing appliance and of the transfer housing are configured for an attachment or removal of the mixing and spray head without a relative rotational movement. 